Catastrophic blowout, new lessons learned

[DanInStPete]

I think the lesson here is don't mount a non ebike 50 rated tire tubeless on a Class 3 bike. Possibly not even with tubes...

I was going about 24MPH when I heard a shotgun blast followed by the sound of my bare rim scraping the pavement. Blew the tire right off the rim, with sealant splattering everywhere. Thought I was going down for sure. Luckily I was going in a straight line and was able to eventually get stopped (heart pounding).

Ordered the Conti Top Contact II tires. With tubes

The tire (Panaracer Gravel King) was fine! I had everything I needed to put a tube in and get home...

 

[indianajo]

Glad you're not injured.
I had a diamondback mtb blow a tube through the gap at a pedal powered 8 mph. I think the fault was an undersized wheel, complicated by Schwinn roll up tires with no wire bead. I replaced with kendas with a bead and stopped having the problem. I imagine Diamondback saved at least $.01 on each sale by leaving a millimeter out of the wheel. Gave that bike away with the kendas on it.

 

[Stefan Mikes]

What a story! I'm putting the Michelin Protek Max inner tubes into my both e-bikes. Marathon e-Plus tyres are already with my Good Ole Mule while I think Specialized Electrak 2.0 on the Vado are proper for the Class 3 e-bike.

 

[DanInStPete]

Edit: I actually ordered the Continental Top Contact II tires which were a better deal. E-Plus or Electrak Armadillo would work as well.

 

[Deacon Blues]

If it had been the front tire you most likely would have gone down....hard.

 

[ruffruff]

yikes

 

[smorgasbord]

I think the lesson here is don't mount a non ebike 50 rated tire tubeless on a Class 3 bike. Possibly not even with tubes...

My understanding is that it's not just that the tire should be rated for tubeless, but that the rim is rated by the manufacturer as well. Do you know if that is the case here?

 

[rich c]

People go down hills a lot faster than 28mph. Not sure your 24mph was the issue.

 

[Mr. Coffee]

My understanding is that it's not just that the tire should be rated for tubeless, but that the rim is rated by the manufacturer as well. Do you know if that is the case here?

That was my first thought as well.

Oh, and in general it is a Bad Idea to ride any e-bike with a non e-bike rated tire. I learned that the hard way with a set of WTB Riddlers, though not so hard as the OP.

 

[DanInStPete]

"Good thing it wasn't the front" That's the mechanic said I didn't really get into it with him, they were busy and he did a service on the bike and trued the rear wheel for me no charge while I waited.

I'm not 100% sure what the issue was. The rims on the Vado don't come tubeless-ready obviously, but the bike shop did the rim tape conversion. Maybe 50 lbs. was too much for running this tire tubeless (likely).

Whatever the case, I'm going tubes and ebike 50 from now on, and will stick to tubeless on my mountain bike only. Tires are already here (1.5 days from Amazon!), and I bought tubes at the shop today so I'll be back in action by tomorrow.

 

[Johnny]

People go down hills a lot faster than 28mph. Not sure your 24mph was the issue.

I second this, 24mph is really not much and many people will exceed it down hill or even flats. I don't think E50 rating is the problem here.

As others suggested check your rims, if tires were installed right etc.

 

[DanInStPete]

Maybe it's that I had more air in them than usual because I just got a Topeak digital gauge and found that my pump was reading ridiculously high. This was probably the first ride with 50 lbs.

I did 600 miles on them and they were still holding air, and I have been up to 30MPH on the bike.

Maybe it was a combination of rim not tubeless specific, air pressure too high, and wrong tires...

 

[nublar]

What was your pressure and what rims/tape/sealant are you using?

 

[E-Wheels]

My understanding is that it's not just that the tire should be rated for tubeless, but that the rim is rated by the manufacturer as well. Do you know if that is the case here?

Yes the rim should also be tubeless rated. Pay attention to the tyre bead groove depth on the rim

 

[Sierratim]

I think the lesson here is don't mount a non ebike 50 rated tire tubeless on a Class 3 bike. Possibly not even with tubes...

I was going about 24MPH when I heard a shotgun blast followed by the sound of my bare rim scraping the pavement. Blew the tire right off the rim, with sealant splattering everywhere. Thought I was going down for sure. Luckily I was going in a straight line and was able to eventually get stopped (heart pounding).

Ordered the Conti Top Contact II tires. With tubes

The tire (Panaracer Gravel King) was fine! I had everything I needed to put a tube in and get home...

Looks like the Gravel King tire is available in several versions, some rated for tubes, others for tubeless. Were yours rated for tubeless installation?

 

[FlatSix911]

I agree, especially downhill MTB riders.. a lot of MTB riders break their frames, bend the wheels, break their fork, and they absolutely abuse their bike.

Going on ebike, flat surface, paved road, only 24mph doesn't sound like much of abuse

Also, as far as I know, urban freeriders do not have ebike rated tires.

Epic video... to be young and dumb again.

 

[DanInStPete]

Ya, Gravel Kings I made sure to order tubeless. The rim was 2020 Vado 5 spec, rim tape was specified and installed by my Specialized dealer, and the sealant was Orange Seal. As I mentioned I had ridden 600 miles on this setup, at up to 30MPH, before the blowout. Perhaps it was just too much air pressure, but I was at 50lbs with the tire rated for 60.

LOVE that vid, supported by Continental, what a coincidence

 

[indianajo]

Thanks for details on bike brand.
I ride 60 psi at all times, since I carry groceries on this bike. Keeps the rims from getting dented. No blowouts on this bodaboda. No schwinn roll up tires, either.

 

[steve marino]

I've never liked the idea of tubeless bike tyres. There's dozens of sharp spokes on a rim, and it only takes one to break and create havoc. True, this could happen w/ a tubed tyre too, but bike rims flex, they're thin walled aluminum, and their narrow design means there isn't much to keep something like this from happening on what sounds like a normal ride and it blew out just because.

When you put a tube in there, the forces are distributed equally because between the air (which is hard at high pressures) there is the rubber tube pressing against the rim and also against the inside of the tyre. It balances the pressures out radially because the more surfaces that are involved, the more the forces are spread out. There is a little give and take. With no tube, forces are acting directly on the tyre itself, hard air against hard rim, and the weakest spot is always going to be the most dangerous and least forgiving spot, right where the tyre clinches onto the rim. High air pressure, aluminum rims that flex especially during cornering, shallow grooves for tyre clinching, no thank you.

 

[DanInStPete]

I think tubeless makes more sense for mountain bikes where being able to ride with very low tire pressures is an advantage. I like the idea of fewer flats on a road bike, but I definitely have trust issues after this.

Mounting new tires with tubes momentarily...